Have you tried the c205 with the m106s?
Nope. That was never the plan. Those two M106 speakers are the entire front line of that HT set-up. I have no dedicated center for that space.
I'm 100% positive the C205 would work with the M106. But I much prefer the sound of a large stereophonic phantom center over a dedicated center channel. To me, it sounds fantastically more cinematic, as the sound completely envelopes the 77" OLED. ...actually the entire front wall, really.
If you have an ideal set-up for a phantom center (14' wide or more front wall), with plenty of space to pull your speakers out from the front wall and corners, and get them positioned perfectly in the room, and center your display within those speakers, I'd give it try for a while. I can literally walk up and down stairs to compare a "center vs. a phantom center", and I know which I prefer - and it's a significant difference. And for those suggesting it doesn't work for people sitting off to the side, we have 4 people sitting across are big sectional during movie night, and every time I'm buried in my "favorite corner", there is zero issue regarding the audio being centered on the screen. We don't sit along the side walls. If you have to sit well outside the boundaries of the speakers, then I'd recommend a center.
This my set up with the M106 speakers — we sit about 8' from the TV... Unless you're on the back-table, then about 12'. You can see a little M8 onwall speakers in the photo with the dartboard. That's one of our two surround speakers. The other is on the facing fall on the other side of the couch - they both face backwards about 15 degrees, to make them less directional. It's a fantastic fairly modest little rig. All powered by the Denon x2600H (Can of worms? LOL)...